There's an oddly over-serious tone to this fairy tale, as if the filmmakers thought they were making a massive action epic on par with The Lord of the Rings. But the plot has all the complexity of, well, a bedtime story. And a little more camp attitude would have helped.

After the gorgeous Ravenna (Theron) marries and then murders a benevolent widower king, she locks his beautiful daughter Snow White (Stewart) in a tower. All the better to continue draining the youth from the entire kingdom. But just as she prepares to take the now of-age Snow's heart, Snow escapes into the woods, and Ravenna hires huntsman Eric (Hemsworth) to find her. Of course, Eric switches sides when he finds her, joining with Snow's childhood sweetheart William (Claflin) and a gang of dwarves to end the evil queen's reign.

Frankly, this project feels like a gigantic marketing ploy, with casting that's so demographically correct that it hurts: the leads are from America, Australia and South Africa, while everyone else is British. Not to mention the Twilight and Thor connections. And what's essentially the plot of The Hunger Games saga. But none of this would matter if the movie was entertaining rather than the leaden slog that it is.

Thankfully, the spectacular art direction holds our attention even when the action slows to a crawl. The costumes make us want to freeze the frame to look at them more closely, and they are inventively integrated with the superior special effects. The cinematography is dense and luxuriant, from the swampy blacks of the dying kingdom to the vividly coloured Pandora-like fairy world into which our heroes escape at one point.

Through it all, Stewart maintains a stony, cold exterior that never lets us in, while Theron channels Faye Dunaway channelling Joan Crawford's bulging eyes and strangled vowels. So it's up to Hemsworth to deliver a surprisingly warm, gruff turn that gives the film an unexpectedly cool final shot. And every scene is stolen by veteran Brits Hoskins, Winstone, McShane, Jones and Frost as the snappy, bustling, hilarious dwarves. Without them, this po-faced, over-ambitious blockbuster would be unwatchable by anyone but teen girls.